Emulsion aggregation (EA) toners are used in forming print and/or xerographic images. Emulsion aggregation techniques typically involve the formation of an emulsion latex of resin particles that have a small size of from, for example, about 5 to about 500 nanometers in diameter, by heating the resin, optionally with solvent if needed, in water, or by making a latex in water using an emulsion polymerization. A colorant dispersion, for example of a pigment dispersed in water, optionally with additional resin, is separately formed. The colorant dispersion is added to the emulsion latex mixture, and an aggregating agent or complexing agent is then added and/or aggregation is otherwise initiated to form aggregated toner particles. The aggregated toner particles are heated to enable coalescence/fusing, thereby achieving aggregated, fused toner particles. United States patent documents describing emulsion aggregation toners include, for example, U.S. Pat. Nos. 5,278,020; 5,290,654; 5,308,734; 5,344,738; 5,346,797; 5,348,832; 5,364,729; 5,366,841; 5,370,963; 5,403,693; 5,405,728; 5,418,108; 5,496,676; 5,501,935; 5,527,658; 5,585,215; 5,650,255; 5,650,256; 5,723,253; 5,744,520; 5,747,215; 5,763,133; 5,766,818; 5,804,349; 5,827,633; 5,840,462; 5,853,943; 5,853,944; 5,863,698; 5,869,215; 5,902,710; 5,910,387; 5,916,725; 5,919,595; 5,925,488; 5,977,210; 6,576,389; 6,617,092; 6,627,373; 6,638,677; 6,656,657; 6,656,658; 6,664,017; 6,673,505; 6,730,450; 6,743,559; 6,756,176; 6,780,500; 6,830,860; and 7,029,817; and U.S. Patent Application Publication No. 2008/0107989.
The disclosures of each of the foregoing patents and publications are hereby incorporated by reference herein in their entireties. The appropriate components and process aspects of each of the foregoing patents and publications may also be selected for the present compositions and processes in embodiments thereof.
Current formulations of toner show a need for improved fusing performance. Poor fusing creates problems in paper adhesion and print performance.
Current formulations of toner show a need for improved flow. Poor flow creates problems in gravity-fed cartridges, causing toner to hang up due to poor flow properties and leads to deletions on paper.
There remains a need for an improved toner composition and process that overcomes or alleviates the above-described and other problems. There further remains a need for a toner composition suitable for high speed printing, particularly high speed monochrome printing that can provide excellent flow, charging, lower toner usage, and reduced drum contamination.